1, 2 and 3 are all spot-on! Weeding in Reserves is my life-long hobby, but for all the reasons you gave, it should not be done without expert knowledge (I’m self-taught but always seeking out experts, books, the experience of others etc) and the best assessment one can make of the ecology there and the role the weed/s are playing in the current situation.
The most valuable lesson I ever had was 23 years ago from a native plant specialist nurseryman visiting a roadside “wasteland” I had been working on. In a weed-covered culvert were several native ferns that I had released from invasive grasses. I asked him if, exposed as they had become, they would survive the coming summer. He said “this one may, this one probably won’t” etc.
He was absolutely right. So by weeding them I killed them.
Ever since I have been trying to improve my ability to assess likely rate of growth of both weed and native, and find the ideal rate and technique of weed-removal to avoid loss of shade and ground cover, while creating and maintaining enough space for the optimum development of the native.
Exactly the same principles apply to trees. Cutting down invasive trees can result in the loss of trees around them…not to mention the loss of fruit that has been feeding birds.
But because I always felt, like you, that interfering with the plants was rightly forbidden, ( though in fact there appear to be no rules about it here) I was extremely thoughtful and cautious from the start, so I was able to learn a lot from a little change, and build up from there.
[EDIT I should have added that I am still not sure when and how much weeding to do, and still occasionally leave what I am pretty sure is a weed, especially seedlings, until I can be 100% sure, eg when its older. And with the current drought here everything has to be rethought entirely.
I was talking with a person recently about the concept of casual volunteers, ie one-day groups, removing weeds in forest reserves and the other person said, “its not rocket science”. I thought a moment, then said, “Actually it IS rocket science”, as it feels like that to me. I am always reviewing the results of what I have done and am increasingly aware of how little I know.
I wish everyone thought like you. We lose a lot of native plants around here from well-intentioned attempts.
So I think you should get some training and get stuck in:)
In Auckland, NZ here we are the Weed Capital of the World, they say. And there is virtually no budget for doing anything about it, so the little work that is contracted is done at the gallop and with chemicals, which is obviously not ideal.
Being a volunteer means I can go off-trail into the fragile forest legitimately, treading lightly and carefully of course. So for me weeding in “my” bit of park is a joy and a privilege I couldn’t live without.